1. Field of the Invention
The present invention relates generally to a disk drive for use with disk cartridges containing a recording disk, and more particularly to a device for opening and closing a shutter of the disk cartridge when the disk cartridge is loaded and unloaded relative to the disk drive.
2. Description of the Prior Art
In recent years, a system for recording and reading information on a recording disk such as a floppy disk or an optical disk has been extensively used. However, with a wide variety of uses in view, the demand for a compact disk drive has increased.
FIGS. 6(a) and 6(b) of the accompanying drawings show one example of generally used disk cartridges. The disk cartridge is a protective container disk cartridge 20 that contains a recording disk 21. The disk cartridge 20 has a shutter 22 for protecting the recording disk 21 against damage which would otherwise be caused mainly by dust. The shutter 22 is slidable in the directions indicated by the arrowheads X1 and X2 and urged by a spring (not shown) in the direction of the arrow X1 so that it is normally held in the closed position shown in FIG. 6(a). When information is to be recorded on, or read from, the recording disk 21, the shutter 22 is caused to slide in the direction of the arrow X2 until it assumes the open position of FIG. 6(b). In this open position, a head window 23 in the cartridge 20 and a window 24 in the shutter 22 are superposed, so that a portion of the recording disk 21 is exposed. Now, information can be recorded on, or read from, the recording disk 21.
FIG. 7 schematically shows a conventional device for opening and closing the shutter of the disk cartridge. The shutter opening and closing device includes a cartridge holder 25 for guiding the disk cartridge 20 (FIGS. 6(a) and 6(b)) as it is loaded on, or unloaded from, a disk drive (not shown). A lever 26 is pivotally movable about a pin 27 secured to the cartridge holder 25. An actuating pin 28 projecting from the free end of the lever 26 is engageable with the disk cartridge 20 and the shutter 22. The cartridge holder 25 has an arcuate guide groove 29 for guiding therealong the actuating pin 28. A tension coil spring 30 is connected at its one end to a first lug 31 on the cartridge holder 25 and, at the opposite end, to a second lug 32 on the lever 26 and urges the lever 26 to turn about the pin 27 in the direction of the arrow R2.
The conventional shutter opening and closing device of the foregoing construction operates as follows.
When the disk cartridge 20 is inserted into the cartridge holder 25 in the direction of the arrow Y1 of FIG. 8, the actuating pin 28 engages a front guide wall 33 of the disk cartridge 20 and a front corner 34 of the shutter 22, as shown in FIG. 8.
As the forward movement of the disk cartridge 20 continues, the front guide wall 33 of the disk cartridge 20 causes the actuating pin 28 to move arcuately along the guide groove 29 in the direction of the arrow R1, as shown in FIG. 9, thereby turning the lever 26 about the pin 27 in the same direction against the force of the spring 30 (FIG. 7). During that time, since the actuating pin 28 is held in engagement with the front corner 34 of the shutter 22 under the force of the spring 30 (FIG. 7), the arcuate movement of the actuating pin 28 causes the shutter 22 to slide transversely in the direction of the arrow X2 against the force of the spring (not shown) disposed in the disk cartridge 20.
When the disk cartridge 20 is fully inserted into the cartridge holder 25, as shown in FIG. 10, the actuating pin 28 displaces the shutter 22 to its leftmost open position in which, as shown in FIG. 6(b), a portion of the recording disk 21 is exposed through the head window 23 of the disk cartridge 20 and the window 24 of the shutter 22.
In the course of the foregoing loading operation, if the forward movement of the disk cartridge 20 is discontinued by releasing the forward pushing force or pressure on the disk cartridge 20, the shutter 22 tends to move in the direction of the arrow X1 under the force of the non-illustrated spring. At the same time, the actuating pin 28 moves arcuately along the guide groove 29 in the direction of the arrow R2 under the force of the spring 30, thereby forcing the front guide wall 33 of the disk cartridge 20 rearward in the direction of the arrow Y2. Thus, the disk cartridge 20 is removed from the cartridge holder 1. This arcuate movement of the actuating pin 28 allows the shutter 22 to move in the direction of the arrow X1 toward its closed position of FIG. 6(a) in which the shutter 22 closes the head window 23 of the disk cartridge 20 to protect the recording disk 21 against the damage.
However, since the lever 26, the pin 27, and the tension coil spring 30 are all disposed on the outside of the cartridge holder 25, the conventional shutter opening and closing device is relatively large in thickness and hence occupies a relatively large space for installation thereof. The conventional shutter opening and closing device of this construction is, therefore, unable to meet the demand for a compact disk drive unit.